[Edit: This is a story of failure. I've struck out the useless & frustrating bits. The only interesting or possibly useful bit is at the bottom.]
This isn't working.... All the guides I've been able to find are terrible. Many broken links, small incomplete sections, nothing covered thoroughly, while trying to cover a huge variety of software and scenarios:
*Using portage to get firmware.
*At least four different sections concerning installing the kernel
*Modifying ebuild files
*Stage 3 downloads
*Stage 4 downloads
*Cross compiling with cossdev
**Creating an overlay
*Compiling using chroot
**Using QEMU virtualization
* Binhost servers (http://bloodnoc.org/~roy/BINHOSTS/gcc-5.x/arm6j/)
That's too much stuff to just touch on and assume that the reader will figure it out. I wasted days trying to work though all that, and I've at least experienced many of those concepts/software before. If you were trying to scare someone off of using Gentoo on a raspberry pi; congratulations: you did a great job! (Jerk.)
Then near the bottom I find this:
Is a working link to a Raspberry Pi 3 image that can be installed by Noobs, and has clear instructions.
I ordered a couple of raspberry pi 3's and I'll wait for them to arrive.
(What a waste...)
In the mean time I started working on my own Gentoo on Raspberry Pi wiki how-to. I don't know if I'm going to be successful; but if I can figure out how to get Gentoo onto a Pi - then I can definitely write a better wiki page about it.